He is a stoic kid. Mr. Spock. He doesn't show emotion. He is a typical kind of muscular farm boy. He is used to lifting stuff.
He essentially has been victimized by Mr. Avery as well.
He felt that if he tried to run away, Steven would have gotten him and it would have been him killed.
In my opinion, putting that before the judge and both families would be very horrible and not fruitful in any way.